The Odeon of Agrippa was a large ancient concert hall located in the centre of the Agora of Athens. It was built about 15 BC. It was a gift to the people of Athens by Marcus Vipsanius Agrippa, a Roman statesman and general.
The capacity was about 1,000 spectators. The hall was equipped with a raised stage and marble-paved orchestra.

After the roof to collapse in around 150 CE, the Odeon of Agrippa was rebuilt as a half-capacity lecture hall. More elaborate facade was added to the north side. Its massive pillars were carved in the form of ‘giants’ (snake tails) and ‘tritons’ (fish tails).